Novel inorganic/organic epoxy based materials were fabricated using both poly(styrene-b-ethylene oxide) (SEO) block copolymer and synthesized TiO2 nanoparticles as modifier. The influence of the ratio between modifiers on the final morphology generated in the investigated epoxy systems was studied by atomic force microscopy (AFM) and transmission electron microscopy (TEM). Results indicated that even for high nanoparticle content. TiO2 nanoparticles synthesized via sol-gel were homogenously dispersed in the epoxy-rich phase. The morphology of the inorganic/organic epoxy based composites consisted of both well-dispersed TiO2 nanoparticles and microphase separated PS block in the continuous PEO block/epoxy-rich phase since block copolymer acted as templating agent for selective location of TiO2 nanoparticles. Differential scanning calorimetry (DSC) was used to study the curing behavior and the influence of the type and quantity of modifier on the glass transition temperature of epoxy matrix. Additionally, optical properties, transparency and UV-shielding efficiency of these new multiphase advanced thermosetting materials were also investigated. (C) 2011 Elsevier Ltd. All rights reserved.